AERATED STATIC PILE - composting system that uses a series of perforated pipes as an air distribution system running under the compost pile and connected to a blower. The pile is not
turned for a period of time (generally 30 days).

AERATION - bringing about the contact of the compost with air through turning, or
by forced or natural ventilation to allow microbial aerobic metabolism.

AEROBIC - occurring in the presence of oxygen. For successful composting, sufficient oxygen
(a minimum of 8% - 12%) should be provided to keep the system aerobic. This ensures that the composting proceeds
optimally and with minimal odor.

AMBIENT TEMPERATURE - the air temperature outside the compost pile.

ANAEROBIC - occurring in the absence of oxygen. Anaerobic composting proceeds slowly and is odiferous.

BIODEGRADABILITY - the potential of an organic substance to be broken down into simpler compounds or molecules through the action of microorganisms.

BULKING AGENT - material, such as wood chips, added to compost primarily to help create good pore structure for air flow. Often provides part of carbon source as well.

BULK DENSITY - the mass of a unit volume of material, generally expressed in gm/cm3. The volume includes both solids and pores. Thus
materials that are light and porous will have low bulk densities, while heavy or compact
materials will have high bulk densities.

CATION EXCHANGE CAPACITY - a measure of the negative charge on soils (primarily on clays and organic matter). It is
defined as the quantity of cations (positive ions) that can be adsorbed by the soil and is expressed in centimoles of charge/kg of soil (6x1023 charged particles are contained in one mole of charge).

CURING - a secondary stage of composting that occurs after much of the readily metabolized material has been decomposed. Provides for additional stabilization and reduction of pathogens and allows further decomposition of cellulose and
lignin, as well as intermediate compounds formed during active composting.

DECOMPOSITION - the breakdown of organic matter through microbial action.

MATURE COMPOST - the stabilized and sanitized product of composting;it has undergone decomposition and
stabilization is complete. It is characterized as containing readily available forms of plant nutrients; it is low in phytotoxic acids.

SOURCE SEPARATION - the practice of separating waste generated within each household or commercial operation into separate fractions such as newspapers, glass etc., and placing them in separate containers for recycling, composting, and disposal.

STABILITY - the degree to which the composted material can be stored or used without giving rise to nuisances, or can be applied to the soil without causing problems due to incomplete degradation of readily biodegradable materials.

THERMOPHILIC - relating to organisms growing at high temperatures
(45C - 70C). A stage in composting.

TOXINS - substances that cause a reduction of viability or functionality in living things.

WINDROW SYSTEM - a composting approach where the mixture is placed in elongated piles called windrows. These windrows are aerated naturally through the chimney effect, or by mechanically turning the piles with a machine or by forced aeration.